Sinusoidal current rectification and ripple cancellation in a very wide three phase AC input to generate a regulated DC output (original) (raw)

Three-phase rectifier with near sinusoidal input currents and capacitors connected on the AC side

Industrial Electronics, IEEE …, 2006

An analysis of a three-phase low-harmonic diode rectifier equipped with inductors, capacitors connected on the ac side, and diodes is presented. Inductors and capacitors are used in conjunction with the three-phase diode bridge rectifier to improve the waveform of the currents drawn from the utility grid. The operation of the proposed converter is analyzed, and on this basis, design considerations are commented. The converter characteristics are determined as a function of the load current. Comparisons between the studied converter and other rectifiers (classical rectifiers with passive or active filters, three-phase rectifiers with near sinusoidal input currents and capacitors connected on the dc side, and three-phase low-harmonic rectifiers applying the third harmonic current injection) are also presented. Several possible applications of the two variants of the three-phase rectifiers with near sinusoidal input currents (with capacitors connected on the dc side or on the ac side) are mentioned. Analytically derived results are experimentally verified.

Improved design of controlled rectifier for reduced ripple resulting from integration of DC loads to AC systems

2014 IEEE PES General Meeting | Conference & Exposition, 2014

In this paper, an improved methodology for the design and precise parameter selection for a controlled rectifier (CR) is presented. We propose an improvement over the existing techniques for inductor and capacitor design based on current ripple, error analysis and switching state analysis. Furthermore, an equation for the design of the DC link capacitor considering the voltage ripple and the switching state analysis is derived. The analysis for the inductor is based on the estimation of the current error area using pulse width modulation (PWM) center and left aligned. This methodology is extendible to Active Power Filters (APF). The proposed methodology is verified through Matlab/ SIMULINK simulation using a predictive current control scheme over the voltage source converter (VSC). In order to show the effectiveness and validity of the proposed methodology; calculations are verified numerically and a comparison with other techniques in the literature is presented.

Digital implementation of harmonics reduction of three-phase boost rectifier

2010

The line currents of three-phase diode bridge rectifier suffer from high THD. This THD is higher than IEEE standards. Injection of six harmonic components to the control signal of the boost converter connected to the three-phase diode bridge rectifier reduces the THD of the utility line current. In this paper a digital implementation of injecting six harmonic to the control signal of three-phase boost rectifier is shown. The digital implementation is carried out by using FPGA. In this study a sin-wave and a triangle-wave with six times the fundamental frequency and variable amplitude are digitally generated in the FPGA. Each signal is added to the dc control signal component of boost converter to be compared with digitally generated saw-tooth. The simulation and experimental results show that the THD of the utility line currents depends on the amplitude and phase-shift of the six-order component injected to the control signal of the boost converter and the angle of input three-phase voltage.

Mitigation of harmonics in three-phase ac system using current injection technique for ac-to-dc converter

Electric Power Systems Research, 2009

This paper presents a new approach to eliminate harmonics and to improve power factor of a three phase front-end uncontrolled rectifier. A high-power-factor is achieved by injecting high-frequency triangular current from the output of three-phase inverter. The high frequency (HF) current modulates the rectifier input voltage resulting in conduction of diodes into each switching cycle. The resulting ac input line current is continuous and sinusoidal in shape with significant reduction in current harmonics. All the switches are operated at zero-voltage switching (ZVS). The diodes of the rectifier are also operated with soft switching at turn-on as well as at turn-off. Varying switching frequency with fixed duty ratio regulates the output voltage. The proposed ac-to-dc converter also maintains high-power-factor even for unbalanced input supply voltages. The analysis of the converter is carried out on a single-phase basis, using different operating modes in one switching cycle of injected current. Theoretical results based on analysis are verified initially through digital simulation, and confirmed by using an experimental prototype of 2.5 kW.

Harmonic reduction in a three-phase rectifier with sinusoidal input current

International Journal of Power and Energy Systems, 2003

This article proposes a new approach to reduce harmonics generated by a three-phase diode rectifier. The proposed approach uses the input filters, six controllable switches, high-frequency isolation transformer, and the three-phase diode rectifier. The switching of the controllable switches is modulated by a novel pulse-width modulation (PWM) implemented in an XC4006 field programmable gate array (FPGA). This approach realizes sinusoidal input current waveforms with low electromagnetic interference and arbitrary output voltage. The output voltage can be controlled by variation of the modulation index in the range (0 ≤ M ≤ 0.98). The experimental results to compare performance between with and without the proposed approach are carried out to confirm its feasibility. http://ieeexplore.ieee.org/xpls/abs\_all.jsp?arnumber=1047184&tag=1

ENHANCED THREE PHASE AC/DC/AC CONVERTER TO MINIMIZING THE TOTAL CURRENT HARMONICS

In this paper, a three phase AC/DC/AC converter with total harmonic distortion THD is used to modify the system and to reducing current harmonics. Throughout each period, the three phase input is planned. The projected converter with voltage contains one main complete value of voltage and adjustments deliver optimal system. In addition, the AC voltage converting to DC by bridge rectifier and the DC convert to DC based on inverter. The total harmonics distortion block tool box is also used. Therefore, the whole system combined with THD has more features against the old system. Lastly, simulink model outcomes are providing to confirm the high performance theoretical analysis of suggested system.

Analysis Of 3-ϕ Multi-Pulse Ac To Dc Converter Through Zig Zag Transformer

2016

This paper deals with the reduction of Total Harmonic Distortion (THD) by using Multi-pulse AC to DC Conversion technique. The three-phase multi-pulse AC to DC conversion system have a phase-shifting transformer and a three-phase source. Every such type of converter provides a 6-pulse AC to DC conversion system, that's why in order to produce more sets of 6-pulse systems, a uniform phase-shift is required and hence with proper phase-shifting angle, 12, 18, 24, 30, 36 and higher pulse systems have been produced. The performance improvement of multi-pulse converter is achieved for total harmonics distortion (THD) in supply current, DC voltage ripples and form factor. This paper presents the discussion of multi-pulse improved power quality ac-dc converter (IPQC) configuration, comparative factors and selection of specific.